The study has shown that the disposition of ceftazidime in this cancer population may be different than that in normal volunteers. The half-life estimates of drug ranged from 1-4.5 hours with a mean of 2.6 hr. compared to a mean of 1.8 hr in normals. Total body clearance in these patients was not different from normals however a significant increase in the distribution volume of drug was observed which led to a prolongation of half-life. Although no drug related toxicity has been observed in these patients, dosage recommendations could be made to reduce the dose and still maintain therapeutic levels above the minimum inhibitory concentration without sacrificing adequate efficacy. Distribution of hybrid rate constant for elimination does not appear to be Gaussion in this population.